Victoria has become the first state in the country to legalise assisted dying for the terminally ill, with MPs voting to give patients the right to request a lethal drug to end their lives from mid-2019.

After more than 100 hours of debate across both houses of Parliament and two demanding all-night sittings, Lower House MPs ratified the Andrews Government's amended bill.

Victorian Health Minister Jill Hennessy said the lengthy debate had given the Parliament the opportunity consider what constitutes a "good death".

"It's one of those things in life — we talk a lot about the start in life, but we don't talk a lot about the end of life," she said.

"We've had some frustrating moments, but ultimately we have landed in a place where Victorians who are confronted terminal illnesses, that are enduring unbearable pains, will have a safe and compassionate option around assisted dying."

Ms Hennessy said experts would immediately start work finalising the scheme, including the type of lethal drug to be prescribed to patients.

"I know this is a disappointment to some people who have terminal illnesses, but the bill does require an 18-month implementation period," she said.

"We have been very dedicated to the task of developing this bill and we're going to be as equally dedicated to the task of getting a safe, sensible and robust system in place."

Government minister Natalie Hutchins missed the vote because she was attending her husband's funeral in New South Wales and was not granted a pair.

Under the legislation, Victorians with a terminal illness will be able to obtain a lethal drug within 10 days of asking to die,after completing a three-step process involving two independent medical assessments.

They must be over the age of 18, of sound mind, have lived in Victoria for at least 12 months and be suffering in a way that "cannot be relieved in a manner the person deems tolerable".